Segmented auger

Abstract

An auger assembled from a plurality of auger segments each of which includes a central longitudinal hollow hub with a longitudinal extension at each end of the hub. A section of helical flighting winds about the hub extending from the extension at one end of the hub to the extension at the other end. The end portions of the helical flighting are beveled to provide an acute edge and a supplementary obtuse edge of the flighting at each end portion. The auger segments have end-for-end symmetry and a plurality of segments are assembled in an end-to-end relationship about a main drive shaft to comprise the auger. When assembled to form the auger, the beveled end portions of adjacent segments overlap in a matching relationship to create a substantially smooth continuous helical flighting surface over the length of the auger. Similarly, the longitudinal extensions of adjacent augers join to create a substantially continuous outer periphery of the assembled hubs. The auger segments are made of an inert material, such as polyethylene, for use in conveying abrasive and corrosive materials.

I claim: 
     
       1. A segmented auger comprising: a. a plurality of auger segments including i. a central longitudinal hollow hub,   ii. a longitudinal extension at each end of said hub,   iii. helical flighting on said hub extending from said extension at one end of said hub to the extension at the other end of said hub,   iv. beveled end portions on ends of said helical flighting each portion including a radial edge at an obtuse angle and a radial edge at an acute angle supplementary to said obtuse angle wherein said beveled end portion tapers from said obtuse edge to said acute edge, and   v. whereby said beveled end portion twists relative to the longitudinal axis of said hub from being substantially aligned with the longitudinal axis near said hub to being at an increasing angle to the longitudinal axis at an increasing distance from said hub; and     b. a drive shaft about which said plurality of said auger segments are assembled end-to-end to provide a substantially smooth and continuous helical flighting surface.   
     
     
       2. The auger as defined in claim 1, wherein said auger segments have end-for-end symmetry. 
     
     
       3. The auger as defined in claim 1, wherein: a. said beveled end portions taper in the direction of the pitch of said helical auger.   
     
     
       4. A segmented auger having auger segments comprising: a. a tubular hub;   b. a substantially semi-circular longitudinal extension at each end of said hub;   c. a pair of coplanar abutment surfaces at the edges of said extensions, one facing in a clockwise direction of rotation and the other facing in a counterclockwise direction of rotation;   d. helical flighting on said hub extending from the counterclockwise facing abutment surface at one end of said hub to the clockwise facing abutment surface at the other end of said hub;   e. beveled end portions on ends of said helical flighting; and   f. whereby said beveled end portion is substantially parallel to the longitudinal axis of said hub near said hub and twists at an increasing angle to the longitudinal axis of said hub at an increasing distance from said hub.   
     
     
       5. The auger as defined in claim 4, wherein: a. said pair of abutment surfaces at each end of said hub define a longitudinal plane of said hub.   
     
     
       6. The auger as defined in claim 4, wherein: a. a plurality of said auger segments are aligned end-to-end and coaxially whereby said beveled end portion of one of said auger segments matches to create a lap joint with a beveled end portion of an adjacent auger segment to provide a substantially smooth and continuous helical flighting surface over the length of the auger; and   b. a main shaft which inserted into said hollow hubs of said aligned plurality of auger segments to operatively link said segments and said main shaft.   
     
     
       7. The auger as defined in claim 6, wherein: a. at least one of the pairs of abutment surfaces of one of said plurality of auger segments abut a pair of said abutment surfaces of an adjacent auger segment.   
     
     
       8. The auger as defined in claim 6, wherein: a. the transverse cross section of said main shaft is a regular hexagon.   
     
     
       9. A segmented auger, comprising: a. a plurality of auger segments including i. a central longitudinal hollow hub,   ii. helical flighting on said hub extending from one end of said hub to the other end of said hub,   iii. beveled end portions on ends of said helical flighting, each portion including an edge along a first radial line of said hub at an obtuse angle and an edge along a second radial line of said hub at an acute angle supplementary to said obtuse angle wherein said beveled end portion tapers from said obtuse edge to said acute edge, and   iv. whereby each of said beveled end portions is substantially parallel to the longitudinal axis of said hub and twists at an increasing angle to the longitudinal axis of said hub at an increasing distance from said hub;     b. a drive shaft about which said plurality of said auger segments are assembled end-to-end to provide a substantially smooth and continuous helical flighting surface.   
     
     
       10. The auger as defined in claim 9, wherein: a. said ends of said hub have one or more longitudinally extended sections and corresponding recessed sections to permit said ends of adjacent auger segments to mate when assembled to form the auger so as to provide a substantially smooth and continuous outer periphery of said hubs about said shaft.   
     
     
       11. A segmented auger, comprising: a. a tubular hub;   b. a substantially semicircular longitudinal extension at each end of said hub;   c. a pair of coplanar abutment surfaces at the edges of said extensions, one facing in a clockwise direction of rotation and the other facing in a clockwise direction of rotation;   d. helical flighting on said hub extending from the counterclockwise facing abutment surface at one end of said hub to the clockwise facing abutment surface at the other end of said hub;   e. beveled end portions on ends of said helical flighting, each portion including an edge along a first radial line of said hub at an obtuse angle and an edge along a second radial line of said hub at an acute angle supplementary to said obtuse angle wherein said beveled end portion tapers from said obtuse edge to said acute edge, and   f. whereby each of said beveled end portions is substantially parallel to the longitudinal axis of said hub and twists at an increasing angle to the longitudinal axis of said hub at an increasing distance from said hub.